Role Of Iodine Research Articles

On the Châtelperronian/Aurignacian Conundrum: One Culture, Multiple Human Morphologies?

Previous articleNext article No AccessDiscussion and CriticismOn the Châtelperronian/Aurignacian Conundrum: One Culture, Multiple Human Morphologies?JeromeE.Dobson and GlennW.GeelhoedJeromeE.DobsonOak Ridge National Laboratory, Oak Ridge, Tenn. 37831/Office of the Dean, George Washington University Medical Center, Washington, D.C. 20037, U.S.A. ([email protected]). 8 viii 00 Search for more articles by this author and GlennW.GeelhoedOak Ridge National Laboratory, Oak Ridge, Tenn. 37831/Office of the Dean, George Washington University Medical Center, Washington, D.C. 20037, U.S.A. ([email protected]). 8 viii 00 Search for more articles by this author Oak Ridge National Laboratory, Oak Ridge, Tenn. 37831/Office of the Dean, George Washington University Medical Center, Washington, D.C. 20037, U.S.A. ([email protected]). 8 viii 00PDFPDF PLUSFull Text Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmail SectionsMoreDetailsFiguresReferencesCited by Current Anthropology Volume 42, Number 1February 2001 Sponsored by the Wenner-Gren Foundation for Anthropological Research Article DOIhttps://doi.org/10.1086/318438 Views: 65Total views on this site Citations: 3Citations are reported from Crossref PDF download Crossref reports the following articles citing this article:Susan J. Crockford Thyroid rhythm phenotypes and hominid evolution: a new paradigm implicates pulsatile hormone secretion in speciation and adaptation changes, Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology 135, no.11 (May 2003): 105–129.https://doi.org/10.1016/S1095-6433(02)00259-3Susan J. Crockford Commentary: Thyroid Hormone in Neandertal Evolution: a Natural or a Pathological Role?, Geographical Review 92, no.11 (Nov 2019): 73–88.https://doi.org/10.1111/j.1931-0846.2002.tb00135.xJerome E. Dobson Comment in Reply: an Interdisciplinary Discourse on the Role of Iodine in Human Evolution, Geographical Review 92, no.11 (Nov 2019): 97–103.https://doi.org/10.1111/j.1931-0846.2002.tb00138.x

A Novel Catalytic role of Molecular Iodine in the Oxidation of Benzylic Alcohols: Microwave-Assisted Reaction

Molecular iodine was used to catalyse the oxidation of several benzylic alcohols to the corresponding ketones under the microwave-irradiated method, and the role of iodine was explored.

The role of iodine in brain development.

I is required for the synthesis of thyroid hormones. These hormones, in turn, are required for brain development, which occurs during fetal and early postnatal life. The present paper reviews the impact of I deficiency (1) on thyroid function during pregnancy and in the neonate, and (2) on the intellectual development of infants and children. All extents of I deficiency (based on I intake (microgram/d); mild 50-99, moderate 20-49, severe > 20) affect the thyroid function of the mother and neonate, and the mental development of the child. The damage increases with the extent of the deficiency, with overt endemic cretinism as the severest consequence. This syndrome combines irreversible mental retardation, neurological damage and thyroid failure. Maternal hypothyroxinaemia during early pregnancy is a key factor in the development of the neurological damage in the cretin. Se deficiency superimposed on I deficiency partly prevents the neurological damage, but precipitates severe hypothyroidism in cretins. I deficiency results in a global loss of 10-15 intellectual quotient points at a population level, and constitutes the world's greatest single cause of preventable brain damage and mental retardation.

Hypothesis: iodine, selenium and the development of breast cancer.

In this paper we examine some of the evidence linking iodine and selenium to breast cancer development. Seaweed is a popular dietary component in Japan and a rich source of both of these essential elements. We hypothesize that this dietary preference may be associated with the low incidence of benign and malignant breast disease in Japanese women. In animal and human studies, iodine administration has been shown to cause regression of both iodine-deficient goiter and benign pathological breast tissue. Iodine, in addition to its incorporation into thyroid hormones, is organified into anti-proliferative iodolipids in the thyroid; such compounds may also play a role in the proliferative control of extrathyroidal tissues. Selenium acts synergistically with iodine. All three mono-deiodinase enzymes are selenium-dependent and are involved in thyroid hormone regulation. In this way selenium status may affect both thyroid hormone homeostasis and iodine availability. Although there is suggestive evidence for a preventive role for iodine and selenium in breast cancer, rigorous retrospective and prospective studies are needed to confirm this hypothesis.

Colloidal aggregates of insoluble inclusions in human goiters

To shed some light on the physicochemical properties of the thyroid follicular colloid, we have screened retrospectively the autoradiographs of 60 human nodular goiters labeled 17 h preoperatively with 100 μCi 125I for evidence of colloid compartmentalization. In 87% (52/60) of all goiters examined, sporadic or multiple colloidal inclusions (`colloid stones') not mixing with newly labeled Tg were detected. The detailed analysis of 17 goiters revealed a mean incidence of 0.09 ± 0.11 `colloid stones' of variable size per follicle ranging from 0.02 ± 0.01 (10) to 0.43 ± 0.09 (5) (mean values ± S.D., number of sections examined in brackets). In this study we did not find a clear-cut association of incidence of `colloid stones' with sex, age or nosologic group (hyperthyroid, preclinically hyperthyroid, euthyroid). The existence of different colloidal compartments as demonstrated in this and other studies is of considerable importance for thyroid function, interpretation of iodine kinetics, and studies on the role of iodine on growth and function of the thyrocytes. Different thyroidal iodine compartments could well be of functional relevance, for example in the adaptation of thyroid hormone secretion to antithyroid drugs or in severe and prolonged iodine deficiency, when very slow compartments become an important source of minimal quantities of iodine and thyroid hormone. `Colloid stones', for example, may well explain the repeatedly observed, surprisingly large total iodine store in human endemic goiters, even in the presence of severe iodine deficiency. It is evident that the existence of multiple iodine compartments and, in particular, of particulate slow-turnover pools complicates the interpretation of total glandular iodine measurements with modern techniques such as X-ray fluorescence and positron emission tomography.

On the Role of Iodine in the Oxidation of Zr in KI Medium

The influence of I2 on the kinetics of spontaneous as well as galvanostatically induced growth of insulating oxide films on Zr metal was studied in KI solutions as a function of concentration. The stability of the anodic oxide films on Zr surfaces was investigated by measuring the potential and the two impedance components of the electrode-solution interface under currentless conditions. In all cases, the passivating oxide films were found to grow with time. The anodic polarization carried out at different current densities produced charging curves whose potentials increases with current density. The presence of increasing amounts of I2 in the KI medium always shifts the potential of ZrO2 films towards more positive values, most probably because the formed triiodide ion (I3 − in the electrolyte enhances the formation of zirconium-iodine species at the electrode surface. A dissolution-precipitation mechanism was proposed which is consistent with the above results as well as with the results of the effect of temperature on the currentless film growth process.

Upper Limit of Iodine Oxide in the Lower Stratosphere

It has been suggested that iodine oxides, IOx, could play a significant role in the ozone destruction in the lower stratosphere. To investigate this suggestion, spectra from nine SAOZ uv-visible spectrometer balloon flights were examined for the IO absorption signature between 405 and 450 nm. IO was not detected, either at mid- or high latitude, in the morning or the evening, in summer or winter. An upper limit of 0.2 parts per trillion by volume (pptv) at 20 km and 0.1 pptv at 15 km at the 95% confidence level (2σ), was derived from the best measurements at 90° SZA at sunset and sunrise. Since a photochemical model shows that 70% of inorganic iodine should be in the form IO at that time, it is concluded that unless iodine chemistry is different from that assumed at the moment, the role of iodine in stratospheric ozone depletion is small.

The Role of Iodine in the Management of Graves’ Disease

The Role of Iodine in the Management of Graves’ Disease

On the role of iodine in ozone depletion

Ozone depletions in the lower stratosphere outside of polar regions are difficult to explain using only local chlorine and bromine chemistry. We speculate that iodine chemistry in combination with trends in anthropogenic chlorine and bromine may also be a factor in determining the widespread current depletion of lower stratospheric ozone. We also speculate on a related role for iodine in the sudden springtime surface ozone loss observed in the Arctic.

The biochemistry of endemic cretinism: roles of iodine and selenium deficiency and goitrogens

The biochemistry of endemic cretinism: roles of iodine and selenium deficiency and goitrogens

The Influence of Iodine on the Intensity of the Intrathyroidal Autoimmune Process in Graves' Disease

Several lines of evidence support an etiological role of iodine for the initiation and perpetuation of autoimmune thyroid disease. However, varying relapse rates after increased iodine supplementation have been reported for Graves' disease. Furthermore the effects of iodine on the intensity of human autoimmune thyroiditis have previously only been investigated by indirect parameters and actions of iodine on thyroid function and a possible enhancement of the intrathyroidal autoimmune process in Graves' disease are difficult to separate in previous studies. Moreover lymphocytic thyroiditis in animal models has always been induced by considerably higher iodine doses as those used in in vivo studies. Therefore we investigated the effect of low and high iodine concentrations on the intensity of the intrathyroidal autoimmune process in Graves' disease. The intensity of intrathyroidal infiltration by lymphocytes, memory T cells, plasma cells and antigen presenting cells was determined by quantitative immunohistologic methods in 38 Graves' disease patients. 12 patients received additional preoperative iodine (group II) and 26 were treated with thiourelene antithyroid drugs only (group I). Urinary and intrathyroidal iodine concentrations were determined by a modified cer arsenite method in both groups. Application of high iodine doses in group II induced a significant increase of kappa and lambda positive plasma cells and interdigitating reticulum cells. This was not observed for activated T cells. There was no correlation between the extent of intrathyroidal infiltration by activated T cells, plasma cells and antigen presenting cells, and intrathyroidal or urinary iodine or intrathyroidal iodine concentrations in group I.(ABSTRACT TRUNCATED AT 250 WORDS)

Autoimmune Thyroid Disease

A considerable proportion of the thyroid diseases is due to aberrant immune reactions toward thyroid antigens. Autoreactivity is considered to be a normal process controlled by several suppressor mechanisms. Malfunction of these suppressor mechanisms may result in autoimmune disease. Mechanisms of self-tolerance, defects in autoimmune disease, thyroid autoantibodies, thyroid autoreactive T cells, several thyroid autoimmune diseases, and the role of iodine in thyroid autoimmune reactivity are addressed.

The role of iodine in thyroid autoimmunity: from chickens to humans: a review.

Evidence has been presented to support the idea that iodine plays an important role in autoimmune thyroiditis. Excessive amounts induce thyroiditis in genetically susceptible animal strains, while intrathyroidal depletion of iodine prevents disease in strains susceptible to severe thyroiditis. While the mechanisms by which iodine promotes thyroiditis is unknown, several hypotheses have been proposed. (1) T and/or B cells may react specifically to iodinated portions of thyroglobulin (Tg) so that severe iodine depletion renders Tg non-immunogenic. (2) A defect in the iodine processing machinery in thyroid epithelial cells of a susceptible person or animal may, in the presence of iodine, result in elevated levels of oxygen or iodine radicals, which could damage membrane lipids or proteins. (3) Defective iodine processing may result in the iodination of lipid or proteins (other than Tg) which could act either as immunogens or polyclonal activators.

The role of iodine in the development of autoimmune thyroiditis.

(1992). The Role of Iodine in the Development of Autoimmune Thyroiditis. International Reviews of Immunology: Vol. 9, No. 2, pp. 167-182.

Evaluation of electrical conduction in iodine-doped polypyrrole

Electrical conductivity of polypyrrole has been measured after doping with different iodine concentrations. A thermally activated electrical conductivity was found which was pseudoohmic and increased with doping level. The results can also be fitted by log σ versusT−1/2 and log σ versusT−1/4 dependences, instead of the Arrhenius log σ versusT−1 dependence. From these results it was concluded that within the experimental scatter no significant distinction can be made between these different temperature dependence laws. Hence these data can only enable one to speculate about the true underlying transport model, rather than to draw decisive conclusions. Electrical conductivity results predicting the role of iodine dopant concentration on the conduction process of semiconducting polypyrrole are discussed.

Liquefaction of coal under mild conditions: Catalysis by strong acids, iodine and their combination

The concept of using an acid coal depolymerization catalyst with a balancing hydrogenation/ hydrogenolysis function to prevent retrogressive reactions forms the basis of this work. A catalytic system based on combining the superacid CF 3SO 3H (triflic acid) with iodine was examined in coal liquefaction under mild reaction conditions. This system was shown to be effective for three types of coal. For example, CF 3SO 3H (25 wt%) I 2(0.5 wt%) in tetralin as solvent gave 79 ± 2% conversion of a Wyodak coal to 54% asphaltenes and 37% oils after 2 h at 300 °C under 6.8 MPa of H 2 pressure using a batch microreactor. Under identical conditions the acid alone gave only 46% conversion, while iodine alone gave 58%. The combined catalytic system also performed well with toluene as solvent; with the higher rank Illinois no. 6 and Pittsburgh seam coals, best results were obtained with 10 wt% acid 0.5 wt% I 2 . Weaker acids such as p-toluenesulphonic acid and sulphuric acid (98%) were less effective than triflic acid in this catalytic coal conversion. From the dependence of product selectivity on the catalytic system and reaction conditions, and from elemental analyses of liquids and residues and 1H and 13C n.m.r. measurements, it is concluded that the main function of the acid is to enhance coal depolymerization to asphaltenes while the (major) role of iodine in the combined catalytic system is to hydrogenate and hydrocrack the asphaltenes to oils. It is important to note that each catalyst alone, triflic acid as well as iodine, can utilize molecular H 2 to liquefy coal. Finally, the combined catalytic system removed more than 50% of the nitrogen and over 90% of the sulphur of the original coal, as shown for Illinois no. 6 and Pittsburgh seam samples.

Correlated autoradiographic and ion-microscopic study of the role of iodine in the formation of ?cold? follicles in young and old mice

The role of iodine in the formation of "cold" follicles (not labeled on autoradiograms after radioiodine administration) was analysed in ICR female mice during aging and involution of thyroid hyperplasia, by use of light and electron microscopy and by comparing autoradiographic and analytical ion-microscopic images for the same follicle in serial sections. The proportion of "cold" and "partly cold" (displaying a patchy or ring labeling pattern on autoradiograms) follicles increased significantly during aging. This increase was more pronounced in old mice fed an iodine-rich diet as compared to mice fed a moderate iodine diet. Similarly, during goiter involution produced by refeeding iodine, the follicular heterogeneity of iodine metabolism was more accentuated with a high dose of iodine, regardless of the age of the mice. The follicular lumina of "hot" and "cold" follicles had the same concentration of stable iodine, as shown by analytical ion microscopy, and the cells of both types of follicles formed colloid droplets in response to TSH. Furthermore, when a goitrogenic treatment was induced in aged mice, some "cold" follicles persisted after 8 days, but all follicles resumed "hot" after 16 days. By analytical ion microscopy, 127iodine was also found inside thyroid cells of old mice, but the cytoplasmic patches of 127iodine were not labeled with 125iodine. They corresponded to lipofuscin pigments and secondary lysosomes, as observed in serial sections at the electron-microscopic level. This intracellular stable iodine could constitute a slow turnover compartment not used for hormone synthesis.

On the susceptibility to stress corrosion cracking of Zircaloy in an iodine containing environment

The role of iodine and zirconium iodide in the process of stress corrosion cracking (SCC) of Zircaloy is studied by an internal pressurization SCC test and independent corrosion and creep tests, using iodine and zirconium tetraiodide crystals as the attacking species. Measurement of the critical values of iodine potential reveals that irradiated fuel rods should possess enough iodine potential to induce SCC failure of Zircaloy cladding. The difference between tests with I 2 and ZrI 4, and the morphology of microcraks at the site of corrosion pits suggest that the quantity of free iodine may play an important role in the crack initiation stage. Although the thick surface oxide can protect Zircaloy from iodine attack, it will rupture under sustaining a tensile stress, and then the iodine-bearing carrier will penetrate through the cracks to supply the necessary iodine potential and to proceed the propagation.

Coordination polymers, 2. Effect of iodine doping on electrical properties of coordination polymers derived from terephthalaldehyde bis(S‐benzyldithiocarbazate)

AbstractThe electrical properties of Mn(II), Fe(II), Co(II), Ni(II), Cu(II), and Zn(II) chelate polymers of terephthalaldehyde bis(S‐benzyldithiocarbazate) (TBDTC) have been studied. Similarly, different concentrations of iodine were doped to these chelate polymers to increase their conductivity for producing a new class of electrical conductive material. The current interest in doping of iodine in chelate polymers is to a great extent due to their possible application in power sources and electrochemical devices. Electrical conductivity of chelate polymers and iodine doped chelate polymers have been studied over a wide range of temperature (∼ 300−450 K). From the electrical conductivity of these polymers activation energies of electrical conduction have been evaluated. A comparison of electrical conductivity and activation energy of electrical conduction of simple and iodine doped polymers has been made and conclusions about the role of iodine in chelate polymers regarding the electrical conductivity have been drawn.

Di-iodothyronine as part of the oestradiol and catechol oestrogen receptor — The role of iodine, thyroid hormones and melatonin in the aetiology of breast cancer

Hypothyroidism and low iodine intake may be important aetiological factors in oestrogen dependent tumours of the breast, uterus and ovary. They are preventable risk factors. Iodine supplementation will hopefully lead to a decreased incidence of these cancers in future generations. The present author proposes that the tyrosyl residue in the hydrophobic oestrogen binding site of the oestrogen receptor is post translationally modified to monoiodotyrosine and hence 3,3′ di-iodothyronine monoamine (T 2) by peroxidase activity. He has previously proposed that various monoamine receptors are also T 2 based. The densities of these receptors are increased in hypothyroidism and they exert control over release of prolactin and other hormones, including melatonin at multiple sites in the hypothalamic — pituitary axis. Melatonin is a metabolite of serotonin and hence melatonin receptors may be T 2 or rT 3 based as well. These factors could be significant in the aetiology of breast cancer as high prolactin and melatonin levels may be protective. Oestrogen receptor density may be increased in hypothyroidism as is certain monoamine receptor density. This would amplify the effect of high circulation oestrogen levels in hypothyroidism and may help explain why hypothyroidism and low iodine intake are risk factors for breast, uterine and ovarian cancer.